A flow meter has been known in which an impeller is disposed in a fluid space and flow quantity of fluid passing through the fluid space is measured by measuring a rotation number of the impeller. The rotation number of the impeller is measured by means of that a detected part fixed to the impeller is detected by a detecting part. The flow meter includes a connector part to which a connector for electrically connecting an outside control section to the detecting part is connected.
Various structures of the connector part have been disclosed. For example, in US 2006/0010975 A1, a structure is disclosed in which terminal pins are provided through a holder (plug part) perpendicularly to a case (cover) to be abutted with terminals of the detecting part and electrically connected with each other.
However, there are following problems in the structure described in the above-mentioned Patent Reference. In other words, since the terminal pins are perpendicularly press-fitted and fixed to the holder, for example, when the connector is pulled off, the terminal pins may be separated from the terminals of the detecting part to disconnect their electric conduction.
Further, as shown in FIG. 3 in the Patent Reference, since the terminal pins and the terminals of the detecting part are abutted with each other in a radial direction of the impeller, a size in the radial direction of the entire flow meter is larger.
Further, in the flow meter described above, trouble or damage of the detecting part or the like may occur due to leakage of fluid from an inflow port, an outflow port or the like, and dew condensation or the like due to temperature change. In this case, in the structure where the holder is locked at two positions like the above-mentioned Patent Reference, detaching of the holder is difficult and thus the detecting part is not speedily replaced.